Valves and fluid amplifiers



P 3, 1954 I o. FALCONER- 3,147,668

VALVES AND FLUID AMPLIFIERS Filed Nov. 10, 1960 5 Sheets-Sheet 1 v v Z5 1lp 5196 22A 2M g 2.2

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Sept. 8, 1964 D. G. FALCONER 3,147,668

VALVES AND FLUID AMPLIFIERS Filed Nov. 10, 1960 5 Sheets-Sheet 4 2; m? wi mi m2 h w A s 2 13 NM on Q0 V s: m2 S A v\ L lldrlv 5 v IE 0 1 v? mfi I 3 3:

' D. er FALCONER VALVES AND FLUID AMPLIFIERS Sept. 8, 1964 5 Sheets-Sheet 5 Filed Nov. 10, 1960 United States Patent 3,147,668 VALVES AND FLUID AMPLIFIERS David Gray Falconer, 1755 Harvard St. NW., Washington, I16. Filed Nov. 10, I960, Ser. No. 68,314 12 Claims. (til. 91-47) This invention relates to fluid amplifiers and valves in general and particularly those which utilize the forces of the fluid which they control for operation.

It is a primary object of this invention to improve upon the valve Patent 2,880,959 issued to me and to enlarge it to include an amplifier working upon the same general principles but being adaptable to any use, not necessarily that of a valve. The specifications describe the amplifier as a unitary article of manufacture applicable to a variety of uses.

Another object of this invention is to provide an amplifier for use with compressible or incompressible fluids which requires an extremely small control force and which amplifies motion and power proportionally to the control force.

Other objects of the invention and improvements described will be apparent from the specifications.

The drawings, for the most part, show a structure only when that structure is an entity of function, omitting superficial considerations and details of manufacturing.

FIG. 1 shows a conventional sectional view and the principal parts of one species of amplifier as a unitary article of manufacture.

FIG. 2 is a section taken at 22 of FIG. 1.

FIG. 3 is a section taken at 33 of FIG. 1.

FIG. 4 is a view taken at 44 of FIG. 1.

FIG. 5 shows a conventional sectional view of an alternate species to that of FIG. 1, not repeating like details of both.

FIG. 6 is a section taken at 66 of FIG. 6.

FIG. 7 is a section taken at 77 of FIG. 6.

FIG. 8 is a section taken at 8-8 of FIG. 6.

FIG. 9 is a section taken at 9-9 of FIG. 6.

FIG. 10 is a section taken at 10-10 of FIG. 6.

FIG. 11 is a conventional sectional view of the amplifier as a unitary article of manufacture applied to a valve.

FIG. 12 is a conventional sectional view of another species of amplifier as a unitary article of manufacture applied to a valve.

FIG. 13 is a partial sectional view of an amplifier control ending adapted to specialized purpose.

FIG. 14 is a ninety degree rotated sectional view of FIG. 13.

FIG. 15 shows a sectional view of another means of orifice control.

FIG. 16 is an end view of FIG. 13.

FIG. 17 is an end view of FIG. 14.

FIG. 18 is a sectional view of another species of amplifier Valve, the same principles of which may be applied to an amplifier as a unitary article of manufacture without the valve.

FIG. 19 is a section taken at 1919 of FIG. 18.

FIG. 20 shows a partially broken-away sectional view of the fluid amplifier principle applied to a measuring device.

FIG. 21 is an end view of FIG. 20.

FIG. 22 shows a partially broken-away sectional view of the fluid amplifier principle applied to measuring devices as another species.

FIG. 23 is an end view of FIG. 22.

FIG. 24 is a conventional sectional view of a typical valve plug adapted to be attached to an amplifier as a unitary article of manufacture.

FIG. 25 is a conventional sectional view of the amplifier valves used in a pneumatic or hydraulic cylinder.

FIG. 26 is a partially broken-away sectional View of two amplifier valves put to use in a hot and cold fluid mixing valve.

FIG. 27 is a partially broken-away sectional view of an amplifier adapted to operate a butter-fly valve.

FIG. 28 is a partially broken-away sectional view of an amplifier valve adapted to a pressure regulator.

FIG. 29 is a conventional sectional view through a two stage amplifier valve composed of a small amplifier valve controlling a larger valve.

In FIG. 1 a housing 9 consists of a tapering bore 7 increasing in diameter until a certain maximum diameter is reached at 10. The bore then decreases in a streamlined tapering chamber 12 and ending in an efiicient orifice 13. At the opposite end of the bore there is provided an axially concentric straight bore 6 and a shaft sealing member 14. A fluid inlet connection enters the housing 9 at 5. An armature, so called because of its reaction in a controllable fluid field, is made up of shaft portion 1 threaded at one end, joined to an increasing tapering member 7A which approximately conforms to the tapered bore 7 in which it rests, the larger diameter ltl-A being joined with a decreasing streamlined taper 12-A. Its operation is as follows: If fluid under pressure is admitted to the inlet 5 and the orifice 13 is uncovered and open to the atmosphere the fluid will be stopped by the shaft seal 14 but will then fill the space between armature 7A and the walls of bore 7 and in like manner fill all the space around decreasing taper 12A. The flow around the latter taper will be laminar because of the streamlined passage formed between it and its mating taper 12 and the flow coefficient of this passage will be higher than the passage formed in between taper 7A and the mating bore 7 when the armature is held toward the bottom of the page. This is because the cross-sectional area of the space formed between taper 7A and taper 7 is small compared to the comparatively great length of taper 7A. This is somewhat comparable to the phenomenon of choking of flow in a long round duct of small diameter but great comparative length. This, of course, occurs even in a polished duct, for, since frictionless passage is impossible, reduction in flow is inexorable. In this case, however, the frictional area is greater, area for area, than in the above analogy to the duct, because in this case there are two walls-that of taper 7A plus that of taper 7. In models constructed, thirty-five times the wall surface found in the duct analogy are found in a valve whose main valve seat measures A diameter. The function of the fluid amplifier will, therefore, be seen to depend upon the comparative coeificient of flow of the space around the streamlined taper 12A which may be as high as .99 and the coefficient of flow around taper 7A which may be as low as .01. A pressure difference will, therefore, result between these two spaces, in consequence of which, the armature will be caused to move toward the top of the page until pressure equilibrium is attained. Furthermore, if orifice 13 is covered by some means or the flow out orifice 13 is obstructed by some means to effect a given reduction in the flow, the pressure in chamber 12 will rise a proportionate amount. As the pressure rises the resulting back pressure will cause the tapered armature to move a proportionate distance toward the bottom of the page. It will be seen that for any given valve structure the response time will be a function of the operating pressure.

In Patent No. 2,880,959 issued to me a similar function to the described is found and until the issuance of that patent the application of the streamlined taper of the character of taper 12 above, in combination with the proportionately opening structure was novel to the art. For, while piston-like structures which provided proportional opening were known, what was not taught was the indispensability of the streamlined, tapering ending to the piston, which moved in a like streamlined taper to the control orifice, in combination with a tapered piston which restricts by means of a long and ineflicient pas-sage the proportional ability of the fluid in this passage from approaching volumetric efliciency of the streamlined exit above the maximum diameter of the piston. It was taught in the above patent that this streamlined taper was essential to function at above a certain level of pressure; the principle applies here that laminar flow must be assured by streamlined design and smooth surfaces in chamber 12 but the exact geometry will depend upon too many other factors to state here.

On taper 7A are indicated finely scribed or etched lines at 15; the use of the lines to obstruct the formation of laminar flow in this space and thereby increase lift force is optional. Various models have been built with this feature but as it was pointed out in the above patent, deep grooves can become a source of functional trouble.

With reference still to FIG. 1, a shaft 1 threaded for work attachment may, according to convenience, be equipped with a jam nut or other fastening means 11 and, if needed, a light spring 16. (In certain cases in which the amplifier is used to operate a valve and a zero pressure differential exists a spring is used to return the valve to its seat.) FIG. 1 shows the amplifier as a unitary article of manufacture adapted to be used, for instance, in FIGS. 11, 12, 16, 17, 18, 23, 25, 28, 29, certain unique modifications being made in these examples as in other practice.

FIG. 2, a section of FIG. 1, taken at 22 shows the blocking of the pass-age of a flow impurity or particle 17 which is too large to enter the passage between the housing wall 6 and the armature shaft 1; if the particle had been smaller it would have entered and would have passed into a larger passage between the tapered bore 7 and the armature taper 7-A of FIG. 3, where it is shown as 18 or 19. Since the diameter of the orifice 13 of FIG. 4 is greater than the width of the two passages just mentioned the particle 18 would pass through without difficulty; this is a sizing or filtering system. A first filter or a strainer, not shown, is advisedly placed somewhere in the inlet line, in addition. It should be noted that the bore 6 serves a triple function, viz: (1) As a filter. (2) As a bearing for the shaft 1 against lateral thrust. (3) As a flow area control; i.e., in some case-s it is desirable to limit the flow entrance to a value not exceeding that of orifice 13.

FIG. 1 shows these species of the amplifier having a round cross-sectional form to the increasing tapered parts 7 and 7-A. This is the easiest to manufacture but since the operation of the device is dependent upon the coefficient of flow of the chamber 12 exceeding that of the space between the tapers 7 and 7-A it would seem that increasing the wall surface of the latter space to impede further the flow would yield greater power because of the greater pressure unbalance. Thus FIG. shows a four-sided pyramidal shape for the armature 2th and the housing recess into which it fits 2@A, the square having more surface than an equal diameter. The large end of this pyramid 21 must terminate in a form designed to make for laminar flow as shown by the decreasing taper 22 and the mating recess 22-A in the housing 23. The other parts of this species are a control orifice 24 and a shaft 25 sliding in a combination filter and bearing 26. While four sides were shown in the figure just described a different number could have been used. However the gain in surface could be off-set by the following occurrence: If, in FIG. 7 the corner 27 is not manufactured dimensionally and geometrically alike then a passage allowing a large flow could be formed which would destroy the pressure unbalance, hence the operation of the amplifier. For an illustration, in manufacturing practice a radius of some determined value and feasibility would have to .be imparted to corner 27 and corner 28 and a tolerance would have to be allowed from these dimensions. This tolerance multiplied by the number of corners would then be a considerable factor tending to allow the fluid to by-pass the very surface it is intended to be impeded by.

In FIG. 11 the amplifier of FIG. 1 is shown adapted to a valve mechanism in which the dotted lines 29 represent the end of the amplifier of FIG. 1, fastened in some convenient means to a valve body 30. In the valve body a lever 31 is attached to the shaft 1 of FIG. 1 by means of a pin 32 inserted in a hole through the shaft, drilled perpendicularly to its axis. The lever 31 is slotted for this pin at 33 and in a similar arrangement it is slotted at 34 to receive pin 35 which is inserted through a hole drilled at right angles through the valve stem 36 which slides in bearing 38 at one end and terminates in a valve plug 39 at the opposite end. A main outlet is shown at 44) which is closed to flow when the plug is brought down against its seat. The lever 31 is pinned to the housing at 37 in such a manner that hinge action is effected. An inlet is shown at 41 feeding into the amplifier at inlet 5 but branching oif in a T to feed the main valve by the conduit 42. Its functional resemblance to the valve of Pat. No. 2,880,959 is obvious; however, this figure shows the versatility of the amplifier for individual arrangements. For instance, a lever advantage of 2:1 is shown here, the amplifier opening a larger valve over one-half of the armature travel. Also, if it be imagined that the conduit 42 is fed from a separate source from inlet 41 (not branching 011 in a T as previously) another advantage will be obtained. Compressed air fed to the inlet 41 could then operate the amplifier while hydraulic fluid could be controlled by the valve 39, the fluid having a separate inlet, of course.

Another species of amplifier is shown in FIG. 12, having a control valve 43, a control orifice 44 and a housing 45. The housing ends in a threaded attachment element 47 and is provided with a sealing ring 46. In the housing is a tapering bore 48A which increases from a minor diameter 4-9-A to a major diameter Ell-A in a long, slow taper; at the major diameter the bore decreases in diameter in a streamline shape 51-A which ends at the orifice 44. Slidably located in the above described bore is a hollow armature 64 of substantially the same tapering'shape but shorter, so that axial movement is permitted. The inner walls of the armature are indicated by 53, the armature ending at this end in a work shaft 54 to which is pinned a lever 55 which in turn is pivoted by a pin at 56. The other end of the lever operates a streamlined valve plug 57. The lever enters the valve plug through a hole in the plugs side, the hole being large enough to allow play or idle plug movement but the plug is pinned to the lever at 58. A streamlined shape is given to the valve recess and passage. An inlet 60 is shown with an in-line relationship to the outlet at 61. A slotted recess is shown at 63 for fluid passage to the amplifier and for space for the lever arrangement; The armature 64 may be designed to have equal mass with the streamlined valve 57 and therefore furnish a counter-balance against G forces in the direction of influencing the opening or closing of the valve. An armature of this type has been built of nylon successfully. When the control valve is in oil? position there is fluid pressure on the inside of the armature equal to that on the outside but since the inside chamber derives its fluid from the far end of the armature through the hole 53, expansion occurs when the control valve is opened and fluid is released, thereby reducing the pressure outside the armature wall between the armature and the bore 484%. This feature permits the use of broader manufacturing tolerances and working clearances. When the armature is made of copper or some good conductor an added thermal control advantage has been found. If the fluid becomes hotter the hollow armature expands; as it expands the clearance is reduced. If the clearance is reduced the armature rises proportionately to the temperature expansion and this opens the valve a proportionately greater distance.

In certain cases the hole 53 of FIG. 12 may be omitted and the valve may be sealed in its hollow state. An approach to the same density of the surrounding fluid may be made. This can, for one thing, reduce G forces effects when the forces are applied normal to the long axis of the armature since the film of fluid surrounding or Wetting the outside of the armature will then support it and no armature-wall contact will occur.

FIG. 13 shows a section through the control end of an amplifier which is generic to all of the species with the exception of the exact form of the orifice. Using the numerals from FIG. 1, the increasing taper of the armature 7-A is shown, its mating bore 7, the streamlined taper 12-A, its mating tapering bore 12 and the housing 9. Since FIG. 14 is an identical section through the amplifier except taken at 90 degrees rotation about its long axis. the same numerals can be used in description. FIGS. 16 and 17 are top views of the control end of the amplifiers of FIGS. 13 and 14 respectively. The orifice 13 of FIG. 1 has been changed in shape in these figures and appears as a long rectangular slot 71. The operation of the amplifier of this species is as follows: If pressure connection is made to the amplifier inlet 5 of FIG. 1 and if a sheet of material such as paper or metal 72 is moved to cover the orifice 71 as shown by the arrows 73 and 74, the flow out of the orifice will be restricted substantially in proportion to the percentage of the orifice area covered. Hence, the pressure in the streamlined tapering bore 12 will change proportionately. This governs the position of the armature. The amplifier may then be attached to either a valve or a measuring scale or to some other useful device.

. FIG. 20 shows two amplifiers of the species illustrated by FIG. 1 but with the modification of orifice 13, as it is shown in FIG. 13 and FIG. 14. The numerals used in FIG. 1, FIG. 13, and FIG. 14 will be used in the description. FIG. 21 is a view of the control orifice end of the amplifier. The amplifier housings 9 are mounted on a plate 81 with the long axis of each parallel to the other. A graduated scale 76 is attached to the work shaft 1 of the amplifier on the left while an arrow pointer 75 is attached to the amplifier work shaft 1 on the right. The application illustrates the measurement of the width of a block of material 82 which is shown covering most of the control orifice 71 on the left and part of the control orifice on the right at 80. The arrow 78 indicates reciprocal movement of the block 82 and the arrows 83 and 77 show the effect of this movement upon the work shafts. It will be seen that if the block 82 is moved from its illustrated position which reads .00125 (scale is shown upside-down) to the right in accordance with the arrow 78 that the scale 76 will move in the direction of the arrow 83 but that the pointer 75 will move a corresponding distance in the direction of the arrow 77. Therefore, the differential of measurement between the scale and the pointer remains constant and therefore what is measured is the total flow area left unblocked by the piece being measured and this is a function of the width of this piece.

A device similar to that just described is shown in FIG. 22 in which two amplifiers which where illustrated in FIG. 1 are used. These amplifiers are shown mounted axially concentric on a plate 84. The numerals used to identify parts of FIG. 1 will be used here in applicable cases. A scale 85 is fastened to the work shaft 1 of the lower amplifier by an arm 91 while a pointer 80 is shown fastened to the work shaft 1 of the upper amplifier by an arm 92. If a piece of material 86 is to be measured for thickness it is inserted between the two control orifices 13. If the material is moved in the direction of the arrow 87 the pointer 80 will move in the direction 88 while the scale 85 will move in the direction 90. As in the previous adaptation, FIG. 20, the differential between the pointer and the scale remains constant and therefore what is measured is the total flow area left unblocked; this, of course is a function of the thickness of the piece being measured.

FIG. 15 shows the control end of an amplifier typified by FIG. 1 and in which the numerals when applicable to FIG. 1 will be used in the description. An arm 93, is attached to the amplifier housing 9 extending to contain a pivot bearing 94 while another arm 95 extends in the same direction as the long axis of the amplifier for a convenient distance, whereupon the arm has a right-angle extension 96. A pivot bearing is contained in the arm extension opposite pivotbearing 94 as shown. A pivoting shaft 98 is retained by these bearings 94 and 97. A plate or vane 99 having holes 101 located according to some planned sequence or program is shown attached to the shaft 98. A jet is located as shown axially concentric with the long axis of the amplifier and its orifice 13. The amplifier and jet assembly can, of course, be duplicated in a plane revolving about the pivoting shaft 98 as an axis so that these amplifiers can be made to do work in sequence. The operation of the device is as follows: The amplifier is attached to a fluid pressure source. Pressure is supplied to the jet 100 from a source and in a direction indicated by 103. If the vane is rotated as indicated by the arrow 102 until the jet is blocked off the flow from the amplifier orifice 13 escapes out of the space 104 and the amplifier orifice is open to that extent to which the jet is blocked off. Note that the holes 101 may be cone-shaped to form nozzles and that the orifice is shown here as similar shape. The amplifier armature will be positioned proportionately to the percentage of maximum flow un-impeded by the jet.

FIG. 18 is used to illustrate the use of piston ring giving variable escape area with stroke. This is shown applied to a valve in this figure but, of course, it can just as well be applied to an amplifier. In FIG. 18 a housing 105 contains an inlet 106, an outlet 107, a valve seat 108, a combination shaft bearing and filter 109, an increasing tapered bore 110, reaching a maximum diameter at 111 and then decreasing in a streamlined taper 112, and ending in a control orifice 113. The control orifice is shown here as an elbow at ninety degrees from the long axis of the figure; this is done to illustrate an alternate arrangement which is possible if the passage 114 is designed to preserve laminar flow. A valve plug 115 is attached to a work shaft 116, which in turn is attached to a grooved piston 117. The piston 117 ends in a streamlined shaped taper 118. A piston ring 119 is fitted into the groove in.

the piston 120. This piston ring can best be seen in a section, FIG. 19, taken at 121 of FIG. 18. The piston, it has been found, can be made of some material like Teflon having a low coefficient of friction and the piston ring is split as shown by 122. It is made in such a manner that its natural tendency is to expand against the walls of the tapered 'bore into which it is inserted. It is obvious, therefore, that as pressure in chamber 123 is lowered as the control orifice is opened by some means that the pressure in the chamber 124, being higher, will move the piston to open the valve until the area formed by thesplit in the piston ring will equal the area of the control orifice. It has been found useful to provide a land on both sides of the piston ring as shown by 125 and 126.

FIG. 24 shows a typical type of valve attachment intended for use on the species of the invention shown in FIG. 1, in which a spring 16 of FIG. 1 is shown. This spring is useful in cases in which at some transient period practically a zero pressure differential exists. The valve plug 127 is shown threaded at 128 for attachment to work shaft 1 of FIG. 1.

A FIG. 25 shows a positionable pneumatic or hydraulic cylinder apparatus in which 129 is a housing. The housing contains or has attached to it the following: A pivot bearing 130 and a pin 131 mounted to the housing by a lug 132. A rocker-arm 133, is pressed over the bearing 130, and the rocker-arm holds at one of its ends a valve plug 134 and equidistant from its pivot at its opposite end a similar valve plug 135. Each of these valve plugs act to position two amplifier valves of a type generically described throughout this specification; one of these plugs is shown governing the opening of amplifier valve 135-A and 1355-13 by virtue of being placed over a common opening to the control orifices of these amplifier valves. The other of these plugs 134 is shown, in like manner, governing the opening of the amplifier valve 134-A and 134-B. The method of making these orifices common is shown by duct 136, which joins 137 and by duct 138, which joins duct 139. An inlet is shown for the main pressure supply at 140, which feeds the valves and amplifiers by a conduit 141. A cylinder is provided having a large diameter in its middle at 142 but tapering constantly toward each end until equal small diameters are reached at 143 and 144. Concentric with the cylinder two bores are provided for a shaft bearing; these are shown at 145 and 146. A shaft seal is provided at 147 .and 148 and a shaft is shown at 149 which carries a piston 150 and two expandable piston rings 151 and 152. The operation of the apparatus can be described as follows: Both amplifier valve 134-13 and 134-A are shown open since the orifice control 134 is shown off its seat. A conduit 153, which is controlled by amplifier 134-B leads to the cylinder chamber at 154. The piston is shown all the way to the left. The amplifier valve 134-A controls the exhaust through conduit 155 and it is shown opened with an exhaust exit to the outside atmosphere at 156. In reverse order both amplifier valve 13S-A and 135-B are shown closed. Amplifier 135-B controls the supply through conduit 157 and the cylinder entrance to this conduit is seen at 158. Amplifier 135'A controls the exhaust through conduit 159, leaving the chamber to the outside at 160 but this is, of course, shown blocked since amplifier valve 135A is closed. Now, this is the condition if one set of amplifier valves opens entirely and the opposite set is closed completely; the exhaust is open to one side and the supply is Zero. If, now, one control valve is placed at one-third open and the other at two-thirds open then on one side the piston and exhaust valve is one-third open as well as a supply valve being one-third open. On the opposite side of the piston an ex- 'haust valve is two-thirds open and a supply valve is twothirds open. For any given setting of the control, therefore, a unique position of the piston will be automatically taken. In FIG. 26 two amplifiers typically described by FIG. 1 with valve adaptors are shown fastened to a plate 161 with their long axis parallel and their orifice control ends facing the same direction. The inlets are shown as 162-A and 162-B, their outlets as 163-A and 163-B. Their control orifices (13 of FIG. 1) are provided with curved ninety degree elbows 164-A and 164-B. The elbows end in an orifice 165-A and 165-B, having a temperature sensing strip of bi-metal 166 mounted by some convenient means so that one end of the bi-metal protrudes into the flow mixture of the main outlets 163-A and 163-13. A showersp'ray 167 is held in front of the eiflux of the two outlets. If inlet 162A is connected to a source of hot water and inlet 162B to cold water a temperature control device will be effected in the following manner: The bi-metal strip 166 is adjusted so that if the water mixture becomes hotter than the set regulated temperature, the bi-metal strip will move toward the orifice 165-A thus reducing the flow of hot water and increasing the supply of cold water until the temperature returns to the set point. The means of setting the sensing element has not been shown since numerous methods will be apparent to those versed in the arts.

FIG. 27 shows the amplifier principle and structure of FIG. 1 adapted to control a butter-fly valve. The numerals from FIG. 1 will be used in the descritpion where they are applicable. In FIG. 27 an amplifier 168, with inlet 5, and control orifice 13, is connected by its work shaft 1 to a linkage of a conventional butter-fly valve 169 which is shown installed in a section of pipe 170.

FIG, 28 shows a typical amplifier valve 171 applied to a pressure regulator. In this figure a housing 172 is shown attached to the amplifier valve at 173. The housing contains or is assembled with the following: a shaft 174, having a small diameter 175, and a large diameter 176 is connected to a fulcrum 177. The housing is bored for a bearing surface for the shaft and is threaded at one end for an adjusting screw 178 which is shown in place backing up a compression spring 179. A sealing ring 180 is fitted into a bored groove 181, the inner diameter of the sealing ring contacting the small diameter of the shaft. A larger sealing ring 182 is provided in a groove 183. Between sealing ring 180 and sealing ring 182 a differential pressure chamber 184 is effected and this chamber is fed by conduit 185 from the main inlet 186. The differential pressure in the chamber is counteracted by the spring 179. A vent 187 leads to the atmosphere and a second vent 188 also leads to the atmosphere. In a manner similar to" that described two more sealing rings 139 and 190 are provided. A lever 191 is shown pinned to a linkage member 192 and this is joined to a pressure sensing device composed of a plate 193, a diaphragm 194, a compression spring 195, a washer 196, an adjusting screw 197, and a housing 198. A vent 1-99 is provided in this housing. A plenum chamber 200 is shown in the main housing 172 which communicates to the outlet 201 of the regulator through conduit 202. A needle valve 203, is shown sliding in a boss of the housing casting 204; the needle valve controls the orifice 205. The top end of the needle valve is rounded at 206 and contacts the lower edge of the lever 191, the upper edge of the le er contacting the point of the fulcrum 177.

The operation of the regulator is as follows: A certain pressure to be maintained in the main outlet 201 and the plenum chamber 200 is determined by the force exerted by the spring and adjusted by the screw 197. This force multiplied by the area of the diaphragm 194 plus the fluid pressure per unit area multiplied by the area of the orifice 205 equals the set pressure. If the pressure in the plenum chamber falls below this value the spring 194 will move lever 191 allowing the needle valve 203 to open until the pressure reaches the set point and so on. This is conventional regulation. However, due to the fact that in the valve of the present invention the needle must move only .001" to .003" to open a large main valve 500 times its area (moreover to the maximum travel of the main valve) closer regulation is maintained. A fluctuation in the main supply pressure is not reflected in the regulated pressure because of the provision of a pressure compensated fulcrum. If the pressure in the chamber 184 which communicates with the supply through conduit 185 drops the spring 179 will move the fulcrum 177 to the left. This action increases the force against the lever 191 derived from the supply pressure against the needle valve. Since this pressure is in the direction of opening it is added to the spring 195 force. The main supply valve opens a greater distance to compensate for a fallingoif of supply pressure. Moving a fulcrum itself is a known device; what makes it practical in the present instance is that the travel of the needle valve is so small that the arc effects can be neglected. In practice it is advisable to provide a spring to aid in lifting the needle valve by using a needle valve with a cap or a head upon which one end of the compression spring can bear while the other end bears against the boss 204.

FIG. 29 shows a housing 207 consisting of a main inlet 208 a main outlet 209 a main valve plug .210 which is connected to the work shaft 211 of an amplifier armature 212. The armature is made up of the increasing taper 213 which reaches its maximum diameter at 214 and then decreases in a streamlined form 215 to a point 236. The armature is located in a bore having a like general shape, consisting of an increasing taper 213-A, reaching a maximum diameter at 214-A and then decreasing in a streamlined shape 215-A and ending in an orifice 216 which forms the inlet to a similar smaller amplifier valve. The latter consists of the inlet just mentioned 216, a valve plug 217, a valve seat 218, and an outlet 219. The outlet is shown ending here; in actual practice it is connected to the main outlet 209 by a conduit which is not shown. The bore of the smaller amplifier valve consists of an increasing taper 221-A, which reaches a maximum at 222-A and then decreases in a streamlined shape 223-A until a control orifice is reached at 224. The valve plug 217 is connected to the work shaft 220 of an armature having an increasing tapered portion 221 reaching its maximum diameter at 222 and then decreasing in a streamlined shape 223. The control orifice is shown closed by a needle valve 225' which extends through the housing wall and ends in a cap 226. A conduit 227 from the control orifice connects with the outlet at 228. A device which was not illustrated in the previous figures is sehown here and consists of an annular bore 229 which serves to reduce the wall thickness of the increasing tapered bore 213-A as shown at 230. This bore 229 provides for thermal expansion and contraction of the armature. The armature is shown hollow by a broken-away section 231. This provides for thermal expansion and contraction also.

In addition, however, a secondary advantage is realized because of the fact that when fluid pressure is released through the control orifice there is a tendency for the walls of both the armature and the annular bore to close in on the allowance passage. This is of particular advantage in reducing the manufacturing tolerances between the armature diameter 213 and the tapered bore diameter 213-A, being more useful in this respect for small amplifiers made of somewhat elastic materials.

An alternative arrangement to the above device can be made to advantage: if the wall 230 is composed of a material having a higher coefiicient of thermal expansion than the armature 213 a temperature controlling element is added. As the fluid rises in temperature the clearance between the armature and the wall will increase, thus causing the armature to return in the direction of its seated position. In the case of the amplifier being applied to a valve as in FIG. 29 this would cause a reduction in fiow through the main valve outlet 209.

If the opposite arrangement to the previous paragraph is made by making the armature 213 out of a material having a higher coeficient of thermal expansion than that of the wall 230, a decrease in the temperature of the flowing fluid would reduce the flow.

The same general principles of the other species of amplifiers operate in FIG. 29. A large gain may be effected if the flow coeificient of the valve plug 217, the seat 218, and the passage around these components is maintained high. Laminar flow in both decreasing chambers 223A and 215-A must be preserved. It will be noted that increasing taper 213 may be shortened relative to the corresponding taper of the other species under these conditions.

The foregoing embodiments of the invention are described only for the purpose of illustration and the scope of the invention is to be determined from the appended claims.

What is claimed is:

1. In a fluid amplifier a first structure being a housing having a recess comprising a first tapering portion formed about a first central rectilinear axis and a second tapering portion formed about the same said first central rectilinear axis, the large end of the said first tapering portion joined with the large end of said second tapering portion, the small end of said first tapering portion of said recess therefore being opposite to the small end of said second tapering portion of said recess on said first central rectilinear axis and a second structure shaped conformably to said recess of said first structure about a second central rectilinear axis but said second structure being smaller and shorter than said recess of said first structure, said second structure fitting inside of said recess of said first structure with said second central rectilinear axis congruently located with respect to said first central rectilinear axis and said second structure is reciprocally movable on said first central rectilinear axis of said recess, an inlet means provided in first structure for introducing fluid to said small end of said first tapering portion of said recess and an orifice provided to vent fluid from said small end of said second tapering portion of said recess and motion take-01f means for coupling the movement of said second structure to an external load.

2. Amplifier as in claim 1 wherein said second structure when held in said first tapering portion of said recess forms an inefiicient flow passage of small cross-sectional area compared to length and extensive frictional surface in contradistinction to the streamlined flow passage formed in said second tapering portion and out said vent, the resulting pressure unbalance existing between said first tapering portion of said recess and said second tapering portion and hence the position of said second structure being governable by the flow permitted out said orifice.

3. Fluid amplifier as in claim 1 wherein said second structure is a hollow shell open to said inlet pressure.

4. Fluid amplifier as in claim 1 wherein said first tapering portion of said recess of said first structure is provided with thin walls and an annular pressure space surrounding said thin walls.

5. Fluid amplifier as in claim 3 wherein said first tapering portion of said recess of said first structure is provided with thin Walls and an annular pressure space surrounding said thin walls.

6. Fluid amplifier as in claim 1 wherein said second structure is hollow.

7. Fluid amplifier as in claim 1 in which said second structure is counter-weighted against mass displacing forces.

8. Fluid amplifier as in claim 1 in which said second structure is guided by bearing means and in which a fluid filter is provided.

9. Fluid amplifier as in claim 1 in which said second structure is provided with an expanding piston ring having a variable opening, said opening being governed by the action of the tapering walls of said first tapering portion.

10. A fiuid amplifier in accordance with claim 1, in which said motion take-off means comprises a mechanical element connected to said second structure and extending outside said housing.

11. In a fluid amplifier, a first structure being a housing having a recess comprising a first tapering portion formed about a central rectilinear axis and a second portion formed about the same said axis, the large end of the said first tapering portion joined with said second portion, the small end of said first tapering portion of said recess therefore being opposite to said second portion of said recess on said first central rectilinear axis; and a second structure shaped conformably to said recess of said first structure about said axis but said second structure being smaller and shorter than said recess of said first structure; said second structure fitting inside of said recess of said first structure on said axis, and said second structure being reciprocally movable on said axis; an inlet means provided in said first structure for introducing fluid to said small end of said first portion of said recess, an orifice provided to vent fluid from said second portion of said recess, and motion take-off means for coupling the movement of said second structure to an external load.

12. A fluid amplifier in accordance with claim 11, in which said external load is a position-indicating device.

References Cited in the file of this patent UNITED STATES PATENTS 2,880,959 Falconer Apr. 7, 1959 

1. IN A FLUID AMPLIFIER A FIRST STRUCTURE BEING A HOUSING HAVING A RECESS COMPRISING A FIRST TAPERING PORTION FORMED ABOUT A FIRST CENTRAL RECTILINEAR AXIS AND A SECOND TAPERING PORTION FORMED ABOUT THE SAME SAID FIRST CENTRAL RECTILINEAR AXIS, THE LARGE END OF THE SAID FIRST TAPERING PORTION JOINED WITH THE LARGE END OF SAID SECOND TAPERING PORTION, THE SMALL END OF SAID FIRST TAPERING PORTION OF SAID RECESS THEREFORE BEING OPPOSITE TO THE SMALL END OF SAID SECOND TAPERING PORTION OF SAID RECESS ON SAID FIRST CENTRAL RECTILINEAR AXIS AND A SECOND STRUCTURE SHAPED CONFORMABLY TO SAID RECESS OF SAID FIRST STRUCTURE ABOUT A SECOND CENTRAL RECTILINEAR AXIS BUT SAID SECOND STRUCTURE BEING SMALLER AND SHORTER THAN SAID RECESS OF SAID FIRST STRUCTURE, SAID SECOND STRUCTURE FITTING INSIDE OF SAID RECESS OF SAID FIRST STRUCTURE WITH SAID SECOND CENTRAL RECTILINEAR AXIS CONGRUENTLY LOCATED WITH RESPECT TO SAID FIRST CENTRAL RECTILINEAR AXIS AND SAID SECOND STRUCTURE IS RECIPROCALLY MOVABLE ON SAID FIRST CENTRAL RECTILINEAR AXIS OF SAID RECESS, AN INLET MEANS PROVIDED IN FIRST STRUCTURE FOR INTRODUCING FLUID 